Space telegraphy.



L. DE FOREST.

SPACE TELEGRAPH.

APPLIGAIIOI rum) JUIE 20. 190?.

926,936. Patented July 6, 1909.

LEE .nE roREs'r, o NEw roa UNITED STATES.

K, N, Y.., ASSIGNOR 'ro DE roREs'r 'nA'mo rEL PnoNE (o, a

sPsc TELEGRAZEHY,

To all whom it may concern:

Be it known that I, LEE DE zen of the United States, and a resident of New York, inthe county of New York and State of ew York, have invented a new and useful Improvement in Space 'lelegraphy, of which the following is a specification.

My invention relates to space tclegraphy and more especially to transmitting systems therefor. v I

The object of my in'vention is to 'pr'ovitl a more eflicient means for controlling the opration of continuously oscillating circuits than exists to-day-in this art.

My invention broadly stated consists in the combination of -a source of practicallycontinuous high-frequency electrical oscillations and an oscillatory circuit, energized by asource 01 vibratory current and so associated therewith as to break up the waves radiated by said' oscillations into groups of.

waves having a rate of emission within the limit of audibility and each group consisting of a large number of waves. f

Several embodiments of my 1nvention are illustrated diagrammatically in the d'rawlngs which accompany and form a part of this specification.

In the drawings, Figure 1 represents a space telegraph transmitting system constructed in accordance with the present invention. igs. 2 and 3 are modifications of the system shown in Fig. 1.

In the figures, 1) is a source of unidirectional electroinotiv'e force,' R R are resistances, inductive or non-inductive, C C C arecondensers, L, L are inductances, 8 represents a ga in which an arc may be created,

' S is a spar -gap, A is a source of vibratory electromotive force, K is a key, M is a transformer, and V isfan antenna connected to earth at E.

In all the figures,the clrouit S C L consti- I l There results therefore the radiation of electutes a source of practically continuous electrical oscillations when connected with the f emission substantially equal to either the enerator 1) through the resistances R. -he circuit S C L is an oscillation circuit capable'ofdeveloping intermittent trains of i electrical oscillations of much lower frequency large in comparisonwith that pOItl0n'( the inductance L which is included in the circuit Specification of Letters Patent.

Application tiled June 20,

FoREs'r, a citithan the continuously oscillating i L, and with this end in view the g be of very large capacity 5 uite Patented m 6, 1909.

1907. Serial No. $379,921.

l S C L. F or example, the circuit S. C L may be constructed to develop oscillations having a frequency of the order ten thousand per second. However," the circuit S i' (1 L maybe designed to' develop oscillamillion per second, and in this case the generator A preferably will be one having arelatively high frequency, so that the spark-' frequency of the oscillation in the circuitS (1 L will'be relatively high.

In Fig.2 the circuit S L C is an oscillation circuit which mayhave the characteristics above set forth in connection ,with the circuit S (7 L. Y r V Ln Fig. 3 the oscillation circuit is connected u a in series. with the are S, and contains thei inductance L, and condenser this circuit being bridged by the condenser U andbeing suitably connected inductively or otherwise through the transformer M, with the circuit of generator-A.

VI '1 V/ i v' .ihe condenser L may be employ ed to preventthe flow of direct current from the generator D through the secondaryol' the transformer M. Y

' The ad'ustable contacts of the circuit- S L with the inductance L and of the antenna with said inductance permit the adjustment of the natural periods'of the continuously oscillating circuit and the antenna system. i l The systems may be used as follows: First, the arc gap S may be set so that the potential developed at its terminals will not produce an arc therein until the key K is closed or; second, the arcga 1 may he so adjusted that an arc is produced therein at all times. In

ciated with the source of continuous electrical oscillations. that the enorgization of said oscillation circuit will control the said l source of continuous electrical oscillations.

tro magnetic waves in groups having a rate of i rate of' vibration of the oscillation circuit or else equal to twice the frequency of the gen-' eratorA or, more generally s 'eaking, to the spark frequency of the oscilations in the oscillation circuit. For example, if the oscillations developed inthe circuit S (I L have a frequency of one million per second and the circuit S L or the-circuit S L has a period of one ten-thousandth second, there tions of any'frequency, for example, one

both cases the oscillation circuit is so asso-.

will be radiated from the antenna V electro- -magnetic waveshaving a wave-train frequency of ten thousand per second, each wave-tra n conslstmg of one hundred complete oscillations havin'g a frequency of one million per second. Or, if the circuit S C L orthe c'ircuit S C L has a period of one-millionth secondor, general, is constructed to develop oscillations having a frequency above thelimit of audibility, and if the generator A develops currents of a frequency of live hundred per second so that the spark frequency of the oscillations in the oscillation circuit is one thousand, then there will be radiated from the antenna V electromagnetic waves having a wave-train frequency of one thousand per second, each wave-train consisting practically of one thousand complete oscillations per second.

By means of the system above described, I am able to effectively control the development of oscillations in a continuously oscillating circuit, and to dispense wlth the devices commonly employed in the receiving myself to the particularsystems which I-have herein set forth for the purpose of more fullydisclosing my invention, inasmuch as said systems may be subject to .a wlde range of variation without departure from the principles involved.

I claim:

1. In a space telegraph system, a source of practically-continuous high-frequency electrical oscillations a radlatm conductor associated therewith, an oscillation circuit associated with said source and arranged to control the same, a source of vibratory electrical energy associated with said oscillation circuit and means for controlling said source of vibratory electrical energy.

2. In a space telegraph system, a circuit capable of developing a practically-continuous train of high-frequency electrical oscillations, a radiating conductor associated ther with, an oscillation circuit capable of developing intermittent trains of electrical oscillat1ons of much lower frequency and associated with the first mentioned circuit, a source of vibratory electromotive force associated with said oscillation circuit and means for controlling said source of vibratory electromotive force.

3. In a space telegraph system, a circuit capable of developing a practically-continuous train of high-frequency electrical oscillations, a radiating conductor associated therewith, a source of electrical energy, connections from said source to said circuit, spark electrodes in said connections, an oscillation circuit including said spark-electrodes, a source of vibratory electromotlve force for saidoscillation circuitand means for controlling said source of electromotive force.

4. In a space telegraph system, a source ol' practically-continuous electrical oscillations of frequency higher than the limit of audibility, a radiating conductor associated therewith, an oscillation circuit capable of developing electrical oscillations of frequency lower than the limit of audibility and associated with said source, a source of vibratory electrical energy associated with said oscillation circuit and means for controlling said source of electrical energy.

In testimony whereof, I have hereunto subscribed my name this 17 da of June "LEE DE FOR-EST.

Witnesses THOMAS I. GALLAGHER, Roscoe KENT. 

